Previously, many different types of structures have been used in endeavoring to provide a cost effective and attractive means for producing an illuminated sign. Generally, outdoor signs having lights inside are fabricated of sheet metal bent or broken into a structured shape to produce the frame. Recently, some prior art has been produced using an extrusion to eliminate costly labor while accomplishing the same purpose and maintaining, or even improving, its appearance. While this type of construction has been available, it has not been entirely successful due to its limited utility and complexity. In most cases the light transmitting sheet is flat and held in place with grooves and gaskets. By contrast, flanged vacuum formed face plates have been lacking, particularly with integral mounting flanges.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however, the following U. S. patents were considered related:
______________________________________ Patent No. Inventor Issue Date ______________________________________ 4,547,987 Stilling Oct. 22, 1985 4,452,000 Gandy Jun. 5, 1984 4,267,657 Kloke May 19, 1981 3,863,372 Stilling Feb. 4, 1975 3,396,483 Stein et al Aug. 13, 1968 3,391,481 Lloyd Jul. 9, 1968 ______________________________________
Stilling, in U.S. Pat. No. 4,547,987, teaches a sign structure having a hinged member around its perimeter and an outer face frame supporting a flat face panel. The hinge is formed integrally with extrusions with opposed convexly and concavely shaped members retained by a screw. The flat face panel is gasketed, or a flexible material is alternately used for a front panel, which is retained around a wrapping member jamming between a portion of the extrusion and an arm.
Gandy in U.S. Pat. No. 4,452,000 discloses a housing formed of metal extrusions with a front cover holding flexible light transmitting material wrapped in a retainer bar. The front cover hinges upwardly with a rounded portion of the extrusion web received into a rectangular recess in the housing serving as a pivot to allow the cover to open. The housing top and bottom are connected to the sides using L-shaped corner brackets inserted into a U-shaped inner edge and screws are secured in a recess holding the frame together. An alternate embodiment utilizes a sheet metal housing.
Kloke, in U.S. Pat. No. 4,267,657, again uses extrusions for an outer casing with a C-shaped groove in the perimeter to which a bead on a leg is added. The leg is inserted into the groove allowing a pivotal rotation of about 45 degrees, while beyond that, an angular disposition to about 70-75 degrees is accomplished with the bead disengaged from the groove. Obviously, the leg is part of a front wall to which a flat element containing advertising is retained. It will be noted that little is disclosed about this element, except a raised portion or frame is illustrated on the perimeter. The walls are connected at the corners with L-shaped connector elements, and the corners of the front and rear walls are formed using corner pieces having biforcated ends and teeth.
U.S. Pat. No. 3,863,372 issued to Stilling teaches a sign box which is formed of extrusion members having complimentary mating formations interacting with a concave surface in the extrusion members. A flat translucent element having peripheral strips is nested into the extrusion of the front panel. The corners of the box are held together with gussets having legs that contain a plurality of teeth and are attached with screws that pass therethrough.
Patents of Stein et al and Lloyd are indicative of the art to which this invention pertains for background purposes, however, little relevance is given to their structure.